Re: PIR Defeat, What To Use?

["Stanley Barthfarkle" <sbarth@xxxxxxxxx>]

"Jen...tel" <poleclimber@xxxxxxxxx> wrote in message
news:1156477581.255051.286570@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
>
> Alex Threlfall wrote:
>> Note that they only defeated a simple PIR, not a Microwave PIR :) Also
>> they moved very fast accross the room,
>
> Ah, good point didn't realize that.  But can we really get installed
> only microwave units? I thought, they were both IR and MW.  If that's
> so, don't you still need the IR to activate along with the MW to get an
> alarm? If they defeated the IR by preventing it from seeing the IR
> given off by a person, even if the MW actvated, wouldn't it still not
> go into alarm because there will never be an IR detection?   I'm not in
> the alarm business so I may be way off base and confusing myself.
> Thanks.



Combination Microwave/PIR motion sensors, known as "Dual-Tech" motion
sensors, are set so that each technology is more sensitive, but requiring
both to trip to activ ate the relay.

BTW- if they "defeated" a PIR by moving through a room very quickly, the PIR
wasn't set up properly to begin with. Proper placement, aiming angle, and
sensitivity adjustment are all vital elements of good catch performance,
while reducing the possibility of false alarms.

A good alarm system consists of "layers" of protection, and not just a
single motion sensor for the interior protection.